Personal computers display various types of data files in list form. Besides displaying the names of the files appended to the files, it is known in the art to display the files in the form of icons that conform to the characteristics of the files. A GUI (Graphical User Interface) in wide use as a method of expressing data in a form reduced in size expresses the nature of data visually in an easily understandable manner by subjecting the substance of the data to a size reduction and displaying the result. Further, images of reduced size referred to as “thumbnails” are used in cases where a plurality of image files obtained by picture-taking using a digital camera are displayed at one time. The same is true not only for files but also with regard to devices. For example, when devices inclusive of a hard disk and printer connected to a network are displayed in the form of a list, a widely used GUI expresses each of the devices by a bitmap icon in such a manner that the devices can be recognized with ease.
By thus using a reduced-size image or thumbnail indicating the nature of data, the general nature of the files and devices displayed in a list can be checked with facility. However, if there are multiple items of similar data, it is difficult to distinguish among these items of data based solely upon file names and thumbnails. Accordingly, in a technique proposed in the prior art, additional information regarding a generated thumbnail image is displayed superimposed on a predetermined position in a form overlapping the thumbnail image (see the specification of Japanese Patent Application Laid-Open No. 2001-337994).
Further, the specification of Japanese Patent Application Laid-Open No. 7-334523 discloses generating thumbnail images as search data and using these thumbnail images in a list display with respect also to data such as audio data that does not possess visual information.
Even though a file once used or a device once connected has been deleted, often the file or device is left displayed without being deleted from a list of “recently used files” or a list of devices provided by the operating system. Consequently, there are instances where the fact that a file or device has been deleted and is no longer usable is ascertained for the first time only when access to the file or device is actually attempted-based upon the list. Hence there is a problem in terms of ease of use. In order to deal with this, the specification of Japanese Patent Application Laid-Open No. 10-283142 describes a technique whereby information concerning a printer that has been connected to a network is accepted via the network and the operating status of the printer is displayed in real time based upon the information accepted.
With the conventional method described above, data and the status of a device, which is the storage location of the data, cannot be displayed simultaneously. Further, even though a technique for clearly indicating the status of a device has been disclosed, the status of the device storing the data and the data that has been stored cannot be displayed simultaneously.